The naysayers would point to the success of 2nd day backs like Brandon Jacobs, Marion Barber and Micheal Turner as well as pointing to the large list of 1st round RB busts. The proponents of 1st round backs can point to the superstar backs that have come from the early picks and insist that the back they want in the 1st round is bust-proof.
Here's the recent (5 year) history of RB yards per year, by round.
| Year | Round(s) | Backs | 1,000 Yards Per Year |
500 Yards Per Year | Average |
| 2008 | 1st | 5 | 1 (Chris Johnson) | 1 (Stewart) | 577 |
| 2008 | 2nd/3rd | 5 | 2 (Forte, Slaton) |
1 (Kevin Smith) | 861 |
| 2008 | 4th-7th | 17 | 0 | 0 | 68 |
| Year | Round(s) | Backs | 1,000 Yards Per Year | 500 Yards Per Year | Average |
| 2007 | 1st | 2 | 2 (Peterson, Lynch) |
0 | 1,313 |
| 2007 | 2nd/3rd | 7 | 0 | 0 | 186 |
| 2007 | 4th-7th | 13 | 0 | 0 | 269 |
| Year | Round(s) | Backs | 1,000 Yards Per Year | 500 Yards Per Year | Average |
| 2006 | 1st | 4 | 0 |
4 (Bush, Maroney, Williams, Addai) |
721 |
| 2006 | 2nd/3rd | 4 | 0 | 3 (MJD, White, Norwood) | 537 |
| 2006 | 4th-7th | 9 | 0 | 0 | 271 |
| Year | Round(s) | Backs | 1,000 Yards Per Year | 500 Yards Per Year | Average |
| 2005 | 1st | 3 | 0 | 3 (Brown, Benson, Cadillac) | 682 |
| 2005 | 2nd/3rd | 6 | 1 (Gore) | 0 | 262 |
| 2005 | 4th-7th | 13 | 0 | 2 (Barber, Jacobs) | 147 |
| Year | Round(s) | Backs | 1,000 Yards Per Year | 500 Yards Per Year | Average |
| 2004 | 1st | 3 | 1 (Steven Jackson) | 1 (Kevin Jones) | 721 |
| 2004 | 2nd/3rd | 3 | 0 |
2 (Julius Jones, Tatem Bell) |
434 |
| 2004 | 4th-7th | 9 | 0 | 1 (Turner) | 173 |
| Year | Round(s) | Backs | 1,000 Yards Per Year | 500 Yards Per Year |
Average |
| Total | 1st | 17 | 4 | 9 | 721 |
| Total | 2nd/3rd | 25 | 3 | 6 | 434 |
| Total | 4th-7th | 61 | 0 | 3 | 173 |
You can find productive backs later in the draft, but for every Marion Barber, Brandon Jacobs or Micheal Turner there are 15 backs that don't do a thing. Even with almost 4 times as many backs the 2nd day picks don't have as many successes as the 1st rounders. Drafting a 1st round back is taking a much larger financial risk to greatly minimize the risk you don't get a capable back.
From this data it would seem like the tipping point is at 721 yards. If you currently have a back that can get 721 yards a season then drafting a first round pick is just as likely to net you an inferior back than an upgrade.